<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <script>
        //while
        /*   var num = 0;
           var i = 1;
           while(i <= 100){
               num += i;
               i++;
           }
           alert(num)*/


        //for
        // var num = 0;
        // for (let i = 0; i <= 100; i++) {
        //     num += i;
        // }
        // alert(num);
        //switch

        var a = "String" ;
        switch (a) {
            case 1:
                alert("number");
                break;
            case null:
                alert("null");
                break;
            case true:
                alert("true");
                break;
            case undefined:
                alert("undefined");
                break;
            case "String":
                alert("string");
                break;
        }


    </script>
</head>
<body>


</body>
</html>